From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Carburetter popping due to sticking valves and cooling issues on the 'DL' Series Phantom III.
| Identifier | ExFiles\Box 131\2\ scan0200 | |
| Date | 15th June 1938 | |
| 1113. To By... from Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux} c. Rm.{William Robotham - Chief Engineer} c. Mx.{John H Maddocks - Chief Proving Officer} c. I.A. SWD? See me Rm{William Robotham - Chief Engineer} Hilee Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux}12/N.15.6.38. "DL" Series Phantom III. There have been two cases of popping in the carburetter due to sticking valves in this series of Phantom III. The popping occurs at approximately 1200 to 1300 engine revs. pulling in top gear with little throttle opening. Is there any valve spring period known at this speed which would have an effect on the valves not closing? Slow running is also erratic. Looking at the valve springs while running in the shop, I could not discern anything unusual. Cooling on this Series. It seems to be the general impression that this series of cars are running much cooler than the six port head. A car on test the other day did not record a temperature higher than 75° C. I am under the impression that a high speed fan is proposed for these cars. If the temperatures are on an average cooler with the four port head, will it be necessary to use the high speed fan. GWH.{George W. Hancock - Head Chateauroux} | ||